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ASYMPTOTIC BOUNDS ON OPTIMAL NOISY channel QUANTIZATION VIA RANDOM coding

IEEE TRANSACTIONS ON INFORMATION THEORY 1994年第6期40卷 1926-1938页

作者： ZEGER, K MANZELLA, V UNIV RHODE ISL DEPT ELECT ENGNKINGSTONRI 02881

Asymptotically optimal zero-delay vector quantization in the presence of channel noise is studied using random coding techniques. First, an upper bound is derived for the average rth-power distortion of channel optimized k-dimensional vector quantization at transmission rate R on a binary symmetric channel with bit error probability epsilon. The upper bound asymptotically equals 2-rRg(epsilon,k,r), where k/(k + r) [1 - log2(1 + 2square-rootepsilon(1 - epsilon))] less-than-or-equal-to g(epsilon,k,r) less-than-or-equal-to 1 for all epsilon greater-than-or-equal-to 0, lim(epsilon --> 0) g(epsilon,k,r) = 1, and lim(k --> infinity) g(epsilon,k,r) = 1. Numerical computations of g(epsilon,k,r) are also given. This result is analogous to Zador's asymptotic distortion rate of 2-rR for quantization on noiseless channels. Next, using a random coding argument on nonredundant index assignments, a useful upper bound is derived in terms of point density functions, on the minimum mean squared error of high resolution, regular, vector quantizers in the presence of channel noise. The formula provides an accurate approximation to the distortion of a noisy channel quantizer whose codebook is arbitrarily ordered. Finally, it is shown that the minimum mean squared distortion of a regular, noisy channel VQ with a randomized nonredundant index assignment, is, in probability, asymptotically bounded away from zero.

关键词： ASYMPTOTIC VECTOR QUANTIZATION NOISY channel joint source-channel coding INDEX ASSIGNMENT

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Wyner-Ziv coding Over Broadcast channels: Hybrid Digital/Analog Schemes

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IEEE TRANSACTIONS ON INFORMATION THEORY 2011年第9期57卷 5660-5672页

作者： Gao, Yang Tuncel, Ertem Univ Calif Riverside Dept Elect Engn Riverside CA 92521 USA

A new hybrid digital/analog scheme is proposed for lossy transmission of a Gaussian source over a bandwidth-matched Gaussian broadcast channel with source side information available at each receiver. The proposed scheme combines two schemes that were previously shown to achieve optimal point-to-point distortion/power tradeoff simultaneously at all receivers under two distinct conditions stated in terms of channel and side information quality parameters. For the two-receiver case, the combined scheme is shown to achieve the same kind of optimality for the entire region in the parameter space sandwiched between those two conditions. Crucial to this result is a new degree of freedom discovered in designing point-to-point hybrid digital/analog schemes with side information. When superimposed with analog transmission, the proposed scheme outperforms all previously known schemes even outside the optimality region in the parameter space.

关键词： Broadcast channels Costa coding hybrid digital/analog coding joint source-channel coding writing on dirty paper Wyner-Ziv coding

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A Unified Approach to Hybrid coding

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IEEE TRANSACTIONS ON INFORMATION THEORY 2015年第4期61卷 1509-1523页

作者： Minero, Paolo Lim, Sung Hoon Kim, Young-Han Univ Notre Dame Dept Elect Engn Notre Dame IN 46556 USA Qualcomm Inc San Diego CA 92121 USA Ecole Polytech Fed Lausanne Sch Comp & Commun Sci CH-1015 Lausanne Switzerland Univ Calif San Diego Dept Elect & Comp Engn San Diego CA 92093 USA

Hybrid analog-digital coding has been used for several communication scenarios, such as joint source-channel coding of Gaussian sources over Gaussian channels and relay communication over Gaussian networks. In this paper, a generalized hybrid coding technique is proposed for communication over discrete memoryless and Gaussian systems, and its utility is demonstrated via three examples-lossy joint source-channel coding over multiple access channels, channel coding over two-way relay channels, and channel coding over diamond networks. The corresponding coding schemes recover and extend several existing results in the literature.

关键词： Analog-digital coding hybrid coding joint source-channel coding network information theory relay networks

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Multiview coding and error correction coding for 3D video over noisy channels

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SIGNAL PROCESSING-IMAGE COMMUNICATION 2015年 30卷 107-120页

作者： Vosoughi, Arash Testoni, Vanessa Cosman, Pamela C. Milstein, Laurence B. Univ Calif San Diego Dept Elect & Comp Engn La Jolla CA 92093 USA

We consider the joint source-channel coding problem of stereo video transmitted over AWGN and flat Rayleigh fading channels. Multiview coding (MVC) is used to encode the source, as well as a type of spatial scalable MVC. Our goal is to minimize the total number of bits, which is the sum of the number of source bits and the number of forward error correction bits, under the constraints that the quality of the left and right views must each be greater than predetermined PSNR thresholds at the receiver. We first consider symmetric coding, for which the quality thresholds are equal. Following binocular suppression theory, we also consider asymmetric coding, for which the quality thresholds are unequal. The optimization problem is solved using both equal error protection (EEP) and a proposed unequal error protection (UEP) scheme. An estimate of the expected end-to-end distortion of the two views is formulated for a packetized MVC bitstream over a noisy channel. The UEP algorithm uses these estimates for packet rate allocation. Results for various scenarios, including non-scalable/scalable MVC, symmetric/asymmetric coding, and UEP/EEP, are provided for both AWGN and flat Rayleigh fading channels. The UEP bit savings compared to EEP are given, and the performances of different scenarios are compared for a set of stereo video sequences. (C) 2014 Elsevier B.V. All rights reserved.

关键词： joint source-channel coding Multiview video coding Unequal error protection Scalable coding Asymmetric coding

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On Predictive coding for Erasure channels Using a Kalman Framework

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2009年第11期57卷 4456-4466页

作者： Arildsen, Thomas Murthi, Manohar N. Andersen, Soren Vang Jensen, Soren Holdt Aalborg Univ Dept Elect Syst DK-9220 Aalborg Denmark Univ Miami Coral Gables FL 33146 USA

We present a new design method for robust low-delay coding of autoregressive (AR) sources for transmission across erasure channels. It is a fundamental rethinking of existing concepts. It considers the encoder a mechanism that produces signal measurements from which the decoder estimates the original signal. The method is based on linear predictive coding and Kalman estimation at the decoder. We employ a novel encoder state-space representation with a linear quantization noise model. The encoder is represented by the Kalman measurement at the decoder. The presented method designs the encoder and decoder offline through an iterative algorithm based on closed-form minimization of the trace of the decoder state error covariance. The design method is shown to provide considerable performance gains, when the transmitted quantized prediction errors are subject to loss, in terms of signal-to-noise ratio (SNR) compared to the same coding framework optimized for no loss. The design method applies to stationary auto-regressive sources of any order. We demonstrate the method in a framework based on a generalized differential pulse code modulation (DPCM) encoder. The presented principles can be applied to more complicated coding systems that incorporate predictive coding as well.

关键词： Differential pulse code modulation (DPCM) erasure channels joint source-channel coding Kalman filtering linear predictive coding quantization

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source-channel coding for Fading channels With Correlated Interference

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IEEE TRANSACTIONS ON COMMUNICATIONS 2014年第11期62卷 3997-4011页

作者： Abou Saleh, Ahmad Chan, Wai-Yip Alajaji, Fady Queens Univ Dept Elect & Comp Engn Kingston ON K7L 3N6 Canada Queens Univ Dept Math & Stat Kingston ON K7L 3N6 Canada

We consider the problem of sending a Gaussian source over a fading channel with Gaussian interference known to the transmitter. We study joint source-channel coding schemes for the case of unequal bandwidth between the source and the channel and when the source and the interference are correlated. An outer bound on the system's distortion is first derived by assuming additional information at the decoder side. We then propose layered coding schemes based on proper combination of power splitting, bandwidth splitting, Wyner-Ziv and hybrid coding. More precisely, a hybrid layer, that uses the source and the interference, is concatenated (superimposed) with a purely digital layer to achieve bandwidth expansion (reduction). The achievable (square error) distortion region of these schemes under matched and mismatched noise levels is then analyzed. Numerical results show that the proposed schemes perform close to the best derived bound and to be resilient to channel noise mismatch. As an application of the proposed schemes, we derive both inner and outer bounds on the source-channel-state distortion region for the fading channel with correlated interference;the receiver, in this case, aims to jointly estimate both the source signal as well as the channel-state (interference).

关键词： joint source-channel coding distortion region correlated interference dirty paper coding hybrid digital-analog coding fading channels

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Diversity Image coding Using Irregular Interpolation

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IEEE TRANSACTIONS ON IMAGE PROCESSING 2021年 30卷 5665-5677页

作者： Goren, Mor Zamir, Ram Tel Aviv Univ EE Syst Dept IL-69978 Tel Aviv Israel Nvidia Corp Mellanox Technol IL-69710 Tel Aviv Israel

Diversity "multiple description" (MD) source coding promises graceful degradation in the presence of a priori unknown number of erased packets in the channel. A simple coding scheme for the case of two packets consists of oversampling the source by a factor of two and delta-sigma quantization. This approach was applied successfully to JPEG-based image coding over a lossy packet network, where the interpolation and splitting into two descriptions are done in the discrete cosine transform (DCT) domain. Moreover, unlike the classical source-channel separation approach - which is designed for a predetermined number of erasures (say, K out of N), hence its distortion does not improve when the channel behaves better than expected - an MD coding scheme aims to achieve a better reconstruction quality when more or all the N descriptions are received at the decoder side. The extension to a larger number of descriptions, however, suffers from noise amplification whenever the received descriptions form a non-uniform sampling pattern. In this work, we examine inter- and intra-block interpolation methods, and show how noise amplification can be reduced by redesigning the interpolation filter at the encoder. Specifically, for a given total coding rate, we demonstrate that an "irregular" interpolation filter is robust to the pattern of received packets over all ( K out of N) patterns, with some degradation relative to low-pass (LP) interpolation in the case where all N packets arrived. We provide experimental results comparing LP and irregular interpolation filters, and examine the effect of noise shaping on the trade-off between the central distortion (receiving all packets) and side distortion (receiving K packets).

关键词： Multiple descriptions source coding JPEG interpolation DCT irregular spectrum joint source-channel coding delta-sigma quantization

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Distributed source-channel coding Based on Real-Field BCH Codes

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2014年第5期62卷 1171-1184页

作者： Vaezi, Mojtaba Labeau, Fabrice McGill Univ Dept Elect & Comp Engn Montreal PQ H3A 0E9 Canada

We use real-number codes to compress statistically dependent sources and establish a new framework for distributed lossy source coding in which we compress sources before, rather than after, quantization. This change in the order of binning and quantization blocks makes it possible to model the correlation between continuous-valued sources more realistically and compensate for the quantization error partially. We then focus on the asymmetric case, i.e., lossy source coding with side information at the decoder. The encoding and decoding procedures are described in detail for a class of real-number codes called discrete Fourier transform (DFT) codes, both for the syndrome- and parity-based approaches. We leverage subspace-based decoding to improve the decoding and by extending it we are able to perform distributed source coding in a rate-adaptive fashion to further improve the decoding performance when the statistical dependency between sources is unknown. We also extend the parity-based approach to the case where the transmission channel is noisy and thus we perform distributed joint source-channel coding in this context. The proposed system is well suited for low-delay communications, as the mean-squared reconstruction error (MSE) is shown to be reasonably low for very short block length.

关键词： BCH-DFT codes distributed source coding joint source-channel coding parity real-number codes syndrome

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Deep source-channel coding for Sentence Semantic Transmission With HARQ

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IEEE TRANSACTIONS ON COMMUNICATIONS 2022年第8期70卷 5225-5240页

作者： Jiang, Peiwen Wen, Chao-Kai Jin, Shi Li, Geoffrey Ye Southeast Univ Natl Mobile Commun Res Lab Nanjing 210096 Peoples R China Natl Sun Yat Sen Univ Inst Commun Engn Kaohsiung 80424 Taiwan Imperial Coll London Dept Elect & Elect Engn London SW7 2AZ England

Recently, semantic communication has been brought to the forefront because deep learning (DL)-based methods, such as Transformer, have achieved great success in semantic extraction. Although semantic communication has been successfully applied in sentence transmission to reduce semantic errors, the existing architecture is usually fixed in terms of codeword length and inefficient and inflexible for varying sentence lengths. In this study, we exploit hybrid automatic repeat request (HARQ) to reduce the semantic transmission error further. We combine semantic coding (SC) with Reed-Solomon (RS) channel coding and HARQ (called SC-RS-HARQ). SC-RS-HARQ exploits the superiority of SC and the reliability of conventional methods successfully. Although SC-RS-HARQ can be easily applied in existing HARQ systems, we also develop an end-to-end architecture called SCHARQ to pursue enhanced performance. Numerical results demonstrate that SCHARQ significantly reduces the required number of bits for semantic sentence transmission and the sentence error rate. We also attempt to replace error detection from cyclic redundancy check to a similarity detection network called Sim32 to allow the receiver to reserve wrong sentences with similar semantic information and conserve transmission resources.

关键词： Semantics Codes channel coding Symbols Transformers Encoding Receivers HARQ semantic communication quantization sentence similarity joint source-channel coding transformer

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Robust stack-run coding for low bit-rate image transmission over noisy channels

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IEEE SIGNAL PROCESSING LETTERS 2002年第7期9卷 196-199页

作者： Pépin, C Raffy, P Gray, RM Docomo Commun Labs USA Inc San Jose CA 95110 USA R2 Technol Inc Sunnyvale CA 94087 USA Stanford Univ Dept Elect Engn Informat Syst Lab Stanford CA 94305 USA

We propose a multiresolution algorithm to jointly optimize a source coder and channel coder. The variable-rate source coder combines an optimal bit-allocation strategy and efficient stack-run coding. This compression scheme, concatenated with appropriate rate-compatible punctured convolutional codes, provides a competitive approach to recent state-of-the-art extensions of zerotree methods to noisy channels. Results show that under the assumption of almost zero probability of decoding error, the proposed scheme provides good performance for a lower complexity.

关键词： bit allocation joint source-channel coding rate-compatible punctured convolutional (RCPC) codes stack-run coding

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